I installed one and now it runs a little rough at idle, more air = needs a tune or something else?
Side note, really opened up the top end

 

If you have an oiled filter, you might have too much oil on it. Also might need to just burn some of it off over the course of a couple of days.

 

It's just your engine choking on all that air it's getting. Doesn't know what to do. If it doesn't clear up in a few ride then start looking for problems. The computer needs to relearn it's idle again.

 

Okay okay, i had it on my old lude a while back, so i just yanked it off, but i hanvt had much chance to drive it yet

 

LT1 or LS1. A filter should not cause a huge change unless something is way off. And no you do not need a tune for a filter.

 

Lol dude, little late to the party.
3.8 actually, and no one said you needed a tune, 3.8s have adaptive computers and relearn things as they go.

 

you didnt clean and re oil it before installing? to answer your question, i would agree with cbr and 3800. maybe have it scanned in a couple days to see if it shows anything. that way if it does throw a code in the future youll know its a new one.

 

So far there is tranny that only chevy can read and double o2 heater circuit malfunction

 

Also its not a knN
its like a piece of pipe and a cone filter

 

where is the filter located and how long a pipe. what brand is it? picture would be better.